You may be right - certainly you are about Microsoft wanting to own every piece of every pie. :-D

I would point out, though, that MeeGo is indeed a single operating system that is targeting each of the markets that Microsoft is targeting with 8 largely incompatible efforts - see http://meego.com. They also have 30+ major corporate partners, from Intel to Nokia to Novell to Electronic Arts to BMW, who believe they can cover the embedded market with a single API and product (though with different graphical shells, all based on QT 4 of course).

So, to your question, "Should they be compatible with one another? ", I'd have to reply with a similar question: "Why should they NOT be compatible with one another?!?" It looks much like internal groups such as NT and CE at Microsoft are targeting overlapping markets with incompatible products; lack of executive leadership results in this mess rather than lack of technical talent.

Just my opinion, of course. I could be wrong, but I've watched this happen to other corporations many times (remember the 68000 / 88000 wars at Motorola, for example?).